<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Web Model Demo</title>
  </head>
  <body>
    <button class="float-button b1" id="start_btn">开始</button>
    <button class="float-button b2" id="pause_btn">暂停</button>
  </body>
</html>
